Abstract: Provided is a plastic cover capable of quantitatively discharging powder, including an upper cover, a powder discharging box, a slidable spoon, a powder feeding box 4, and a spring, wherein the upper cover is screwed on the powder discharging box, the slidable spoon is arranged between the powder discharging box and the powder feeding box, the spring is arranged in the slidable spoon, with one end being connected to the powder feeding box and the other end connected to the slidable spoon. With the plastic cover capable of quantitatively discharging powder, the powder can be taken out quantitatively, and the structure is simple, the use is convenient, and the operation is easy.